Buggy code:
public class Database { private static int userID ; private static Connection con = null ; private static Integer [ ] cacheStats ; private static String cacheType ; private static Vector cacheStudentsName ; private static ArrayList < String [ ] > cacheFormulaSettings = new ArrayList < String [ ] > ( ) ; private static ArrayList < Item > cacheinventory = new ArrayList < Item > ( ) ; public static boolean getConnected ( ) { } public static boolean createAccount ( String inputName , String inputPass , String inputType ) { } public static boolean isValid ( String inputName , String inputPass ) { } public static void cacheStats ( ) { } public static void cacheType ( ) { } public static String getType ( ) { } public static Integer [ ] getStats ( ) { } public static boolean setStatus ( Integer [ ] status ) { } public static int getId ( ) { } public static void close ( ) { } public static boolean setFormula ( int monsterLevel , Sign sign , Digits digit , Terms term ) { } public static boolean setFormula ( int studentId , int monsterLevel , Sign sign , Digits digit , Terms term ) { } public static String [ ] getFormulaFromCache ( int monsterLevel ) { } public static String [ ] [ ] getFormula ( int monsterLevel ) { } public static String [ ] [ ] getFormula ( int studentId , int monsterLevel ) { } public static void cacheStudents ( ) { } public static void cacheFormulaSettings ( ) { } public static Vector getNames ( ) { } public static void cacheInventory ( ) { } public static ArrayList < Item > getInventory ( ) { } public static void saveInventory ( ArrayList < Item > items ) { } public static void saveAccuracy ( int answeredCorrectly , int answeredIncorrectly ) { } public static String [ ] [ ] getRank ( ) { try { PreparedStatement select = Database . con . prepareStatement ( "Select<seq2seq4repair_space>Login.lastname<seq2seq4repair_space>,<seq2seq4repair_space>Login.firstname,<seq2seq4repair_space>StudentAccuracy.answeredCorrectly,<seq2seq4repair_space>StudentAccuracy.answeredIncorrectly<seq2seq4repair_space>from<seq2seq4repair_space>StudentAccuracy<seq2seq4repair_space>left<seq2seq4repair_space>join<seq2seq4repair_space>Login<seq2seq4repair_space>on<seq2seq4repair_space>StudentAccuracy.studentID<seq2seq4repair_space>=<seq2seq4repair_space>Login.userID<seq2seq4repair_space>where<seq2seq4repair_space>StudentAccuracy.teacherID<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>order<seq2seq4repair_space>by<seq2seq4repair_space>Login.lastname<seq2seq4repair_space>DESC" ) ; select . setInt ( 1 , Database . getId ( ) ) ; ResultSet res = select . executeQuery ( ) ; int numberRows = 0 ; if ( res . last ( ) ) { numberRows = res . getRow ( ) ; res . beforeFirst ( ) ; } String [ ] [ ] record = new String [ numberRows ] [ 4 ] ; while ( res . next ( ) ) { int answeredCorrectly = res . getInt ( 3 ) ; int answeredIncorrectly = res . getInt ( 4 ) ; record [ ( numberRows - 1 ) ] [ 0 ] = ( ( res . getString ( 1 ) ) + ",<seq2seq4repair_space>" ) + ( res . getString ( 2 ) ) ; record [ ( numberRows - 1 ) ] [ 1 ] = ( ( Integer ) ( answeredCorrectly ) ) . toString ( ) ; record [ ( numberRows - 1 ) ] [ 2 ] = ( ( Integer ) ( answeredIncorrectly ) ) . toString ( ) ; <START_BUG> record [ ( numberRows - 1 ) ] [ 3 ] = ( ( Integer ) ( answeredCorrectly // ( answeredCorrectly + answeredIncorrectly ) ) ) . toString ( ) ; <END_BUG> numberRows -- ; } return record ; } catch ( SQLException e ) { System . out . println ( ( "Error<seq2seq4repair_space>from<seq2seq4repair_space>saveAccuracy:<seq2seq4repair_space>" + ( e . getMessage ( ) ) ) ) ; return null ; } } public static void cleanUp ( ) { } No newline ; at end ; of file ; }

Fix:
record [ ( numberRows - 1 ) ] [ 3 ] = ( ( ( Long ) ( Math . round ( ( ( answeredCorrectly * 100.0 ) // ( answeredCorrectly + answeredIncorrectly ) ) ) ) ) . toString ( ) ) + "%" ;